// data() {}
// let obj = {
//     name:'小明',
//     age: 18
// }
    // obj.age = 28
    // console.log(obj)
    let obj = {}
    let val = 20
    Object.defineProperty(obj,"age",{
    get() {
        console.log(`age属性被读取${val}`)
        return val;
    },
 
    set(newVal) {
        console.log(`age属性被读${newVal}`)
        val = newVal
    }
})